Clay Hardin, a Deputy U.S. Marshal, is about to turn in his badge and take the job as the territory's Indian commissioner until the notorious Ben Thompson slays the marshal when he tried to make an arrest. Clay turns his back on a white-collar job and his girl to pursue the gang. Picking up a bounty hunter and a beautiful half-breed woman along the way, the little band follows the trail into Apache land where the lawman discovers that the outlaws plan to sell repeating rifles to the Indians.

When author Charles Regnier returns to Paris with a best-selling book that criticizes the government, he's tormented by frequent blackouts. After a mysterious cat-like creature slaughters people close to him, Charles is suspected of murder. Charles fears that he is the beast, but his paramour Marie and best friend Henry, believe he's innocent... until the creature begins to stalk Marie.